This invention relates to poultry feeders with adjustable feed levels and of the general type disclosed in U.S. Pat. No. 6,050,220 which issued to the assignee of the present invention and also disclosed in the references cited in the ""220 patent. The invention also relates to a system or unit which controls the distribution of feed from a feed supply hopper through a horizontal conveyor or distribution tube enclosing an auger driven by an electric motor and gear reducer unit, such as, for example, the feed distribution system disclosed in U.S. Pat. No. 3,330,255. As shown in this ""255 patent, the poultry feed is conveyed from a feed supply hopper 10 through a horizontal feed distribution tube or line 11 to a series of feeder pans 12 spaced along the feed distribution tube or line. The feed line or tube encloses a helical feed screw or auger 32 driven by an electric motor and gear reducer unit 33.
In such a feed distribution system, it is common to control the auger drive motor with a paddle actuated switch mounted on the drop tube of the feeder pan located at the end of the feed distribution line, opposite the feed supply hopper. For example, the ""255 patent discloses in FIG. 10 a feed sensing switch 37 and a pivotal actuating paddle or flap 65. When feed builds up in the drop tube, the pressure or force from the feed pushes against the paddle or flap which actuates the switch 37 to shut off the drive motor 33 for the auger 32 within the feed distribution tube or line 11. Capacitive type proximity switches or sensors have also been used to sense a build up of feed within the drop tube, but the switches are not reliable, usually due to an accumulation of feed on the lens of the sensor and do not provide for convenient and precise adjustment.
The present invention is directed to a poultry feeder having an improved control system or unit which is more sensitive and reliable than previously used feeder control systems and which is also conveniently adjustable and constructed to provide high durability and resistance to the conditions of dust and humidity commonly found in a poultry or broiler feeder house. In accordance with a preferred embodiment of the invention, a poultry feeder is constructed as disclosed in above mentioned U.S. Pat. No. 6,050,220. The feeder incorporates a control unit within the bottom pan of the feeder for controlling the motor which drives the auger within the horizontal feed distribution or conveyor tube for delivering feed to a plurality or series of poultry feeders connected to the tube at longitudinally spaced intervals. The illustrated control unit incorporates a cylindrical base housing which is recessed within a center hole of the feeder pan and supports an inverted cone member for slight vertical movement relative to the housing. The cone member is biased upwardly by a spring and is covered by a flexible rubber-like diaphragm having a skirt portion which is pinched between the pan and the housing.
The cone member has a downwardly projecting center plunger or stem which carries a metal actuator screw, and the screw head operates an inductive type proximity switch enclosed within the housing and connected to control the motor for the auger within the feed conveyor tube. The inverted cone member senses the weight of the feed on the cone member and moves downwardly relative to the base housing. When the head of the metal actuator screw is sensed by the proximity sensor or switch, the switch shuts off the auger drive motor. The housing and the actuator cone are molded of a rigid plastics material, and the metal actuator screw is adjustable within the center stem of the cone member for precisely selecting the weight of feed necessary to actuate the proximity sensor.
Other features and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims.